| Cucumber (Cucumis sativus L.) is one of the most chilling-sensitivecrops. Chilling is an important environmental factor that limits thegrowing season of cucumber and adversely affects fruit quality andproductivity.In order to optimize of the cold resistance identification andevaluation system, accelerate molecular marker assisted breedingprocess of chilling resistance in cucumber, in this study,6cucumberinbred lines were used. Low temperature were given to them during theseed germination period and seedling period(first-true leaf stage),respectively. The evaluations of chilling resistance of each inbred linethrough the low temperature seed germination ability and seedlingdamage index. Among the6inbred lines, line0839had a highestchilling resistance in both seed germination period and seedling period;and line B52was the most sensitive to the chilling stress. Therefore, line0839and B52were selected to construct the colony, and for the furtherresearch.Highly resistant inbred line0839, highly susceptible cucumber inbred line B52to chilling, the F1, and F2populations were used in thegenetic research of chilling resistence. The seedlings were exposed tolow temperature for identification of the molecular markers linked to themajor chilling resistant gene in cucumber. A combination of BulkedSegregant Analysis (BSA) and SSR techniques were applied to the F2population, the molecular marker mapping of the linked genes with theresistance to chilling was achieved. The results showed that theresistance to chilling was mainly controlled by a dominant gene. By thegenetic analysis of the F2population, one marker SSR07248wasidentified to be linked to the major resistant gene. The genetic distancebetween the resistant gene and the marker was32.6cM, and located onthe downstream of the SSR07248. |
